Dark Sky (whose future is in question due to the Apple acquisition) has a Time Machine feature that lets you see weather pretty much arbitrarily far in the future: https://darksky.net/details/40.7127,-74.0059/2020-12-31/us12...
will be upper 80s, low 90s. Chance of thunderstorms in afternoon.
Congrats, i have now predicted a typical 4th of July and will be correct more than normal. Damn i should have built a web company and sold my ideas for a bajillion dollars
But I still appreciate that the Dark Sky feature isn't artificially limited to a particular date. They have a nice error bar on the temperature that gives you an indication of how much it's unknown.